The present invention relates to an installation for shaping a part, which can be applied to hot forming methods.
Hot forming methods are used for certain parts such as the hollow fan blades of a turbo-reactor, which are shaped from an assembly of three sheets of titanium, two of which constitute the skins of the blades whilst the third, intermediate, is worked into stiffeners which extend from one skin to the other in a cavity formed between them. The manufacture of these parts requires a hot diffusion bonding operation to unite the sheets at the leading and trailing edges, then the bulging of the internal cavity, still at high temperature, by progressive introduction of a gas such as argon or helium. This is carried out in specific presses comprising a lower die and an upper die which can be joined together to contain the preforms of the blades and to profile their shape. The dies are enclosed in a furnace and brought to the required temperature. The shaping time for the parts is several hours and, apart from the shaping stage, comprises fairly long stages for loading the preforms and placing them in the right position on the lower die, for re-heating the dies and the preforms each time the furnace is opened, and finally for extracting the shaped parts from the furnace. Reference can be made to the document EP-A-0 765 711 for a complete description of the manufacture of such hollow blades.
The aim of the invention is to raise the production rate of parts without having to multiply the number of shaping installations. To resume, the furnace is divided by an insulating wall into at least two compartments making it possible to carry out the operation of shaping one part in one of the compartments while another part is being introduced into the other and set to heat, or is extracted from it. Thus, one element of the operations linked to the shaping is carried out in concurrent operation time in a series production procedure.
The shaping installation is more precisely characterised in that the furnace comprises two superposed parts, with one upper carrying part for the upper die and a lower part, carrying two examples of the lower die present in respective compartments, the upper part being mobile relative to the lower part in such a way that the upper die covers the examples of the lower die alternately, a dividing wall separating the compartments.
In a preferred embodiment of the invention, the furnace is defined by a horizontally mobile plate carrying the examples of the lower die, a fixed wall comprising a lateral boundary and a roof, together with a vertically mobile wall, carrying the upper die and comprising a lateral boundary, connected through a drilling in the roof of the fixed wall and comprising the dividing wall, plus a roof.